Thyroid Hormone Regulation of Thyrotropin α- and β-Subunit Gene Transcription
Thyroid Hormone Regulation of Thyrotropin α- and β-Subunit Gene Transcription
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甲状腺激素对促甲状腺素 α 和 β 亚基基因转录的调节
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发表时间：
1985
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影响因子：
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通讯作者：
I. Kourides
中科院分区：
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作者：
J. A. Gurr;I. Kourides
本文研究了甲状腺激素对甲状腺功能低下小鼠甲状腺肿瘤(IAK109D和109F)促甲状腺激素α亚基和β亚基基因转录的影响。在分离的核中，通过允许在[α-32P]UTP存在下完成体内启动的RNA链，以及通过将标记的RNA转录产物与含有α或βcDNA序列的过滤结合的质粒杂交来测量基因转录。用3，5，3‘-三碘-L-甲状腺原氨酸(T3)(5μg/100g体重)处理荷瘤动物2小时后，TSH-β基因转录水平下降到对照水平的10%，而α-RNA合成水平下降到对照水平的59%。在T3处理6小时后，TSH-β基因的活性仍然受到抑制，而α基因的转录略有上升，仅为对照的77%。用~(32)P标记的含α或βcDNAs的质粒探针进行斑点杂交，检测α和TSH-β基因在T3处理2小时后的肿瘤含量无明显变化，但均明显减少。
ABSTRACT We studied the effect of thyroid hormone on the transcription of the genes for the α- and β-subunits of thyrotropin (TSH) in thyrotropic tumors (IAK 109D and 109F) carried in hypothyroid mice. Gene transcription was measured in isolated nuclei by allowing completion of RNA chains initiated in vivo in the presence of [α-32P]UTP and by hybridization of labeled RNA transcripts to filter-bound plasmids containing α or TSH-β cDNA sequences. Treatment of animals carrying tumor IAK 109D with 3,5,3′-triiodo-l-thyronine (T3) (5 μg/100 g body weight) for 2 hr reduced TSH-β gene transcription to <10% of control levels, whereas a RNA synthesis was reduced to 59% of control. The inhibition of TSH-β gene activity was maintained after 6 hr of T3 treatment, whereas α gene transcription rose slightly to 77% of control. The tumor content of α and TSH-β mRNA, determined by dot blot hybridization with 32P-labeled plasmid probes containing α or TSH-β cDNAs, was unchanged after 2 hr of T3 treatment, and each was reduc...